A common question is whether or not a lifter should keep the hook grip overhead in the snatch. This is one of those issues that doesn't have a simple answer: what works best can vary among lifters.
The main issue while holding a barbell overhead is stability: obviously the athlete needs to be able to support the weight. The hand and wrist need to be able to settle in under the weight of the bar to create a cradle that balances the weight properly and doesn't cause injury. Lifters need to condition the joints over time to this stress, but a proper position is imperative.
Where the hook grip comes into play is simple: the lift starts with it. The lifter has the choice to maintain it or release it overhead. For many people, holding the hook grip limits the mobility
of their hands and wrists too much to allow the proper position overhead
. Others may have better mobility, but holding the hook grip causes pain in the hand or wrist that doesn''t improve with time. The final group has no problem at all achieving the proper hand and wrist position overhead and has no pain when holding the hook.
This last group seems to be comprised of more women than men. I suspect this is simply a product of women generally being more flexible and the diameter of women''s bars being smaller and their hands being more slender; this allows more movement of the hand and wrist even with the hook grip. Men tend to be tighter in general, and with thicker hands and thicker barbells, it's less common for them to be able to get the hand and wrist into a comfortable settled position with the thumb still hooked. It's also more difficult to keep the grip relaxed adequately for this good position when the hook grip is maintained.
For those who can hold the hook grip overhead without a problem, the answer is keep it IF it helps you stay connected to the bar and overall improves your lifts. For those who can't, you'll need to learn to release it at the right time and in the right way. The key is that the grip can't be relaxed while you're still pulling against the bar; an early release will mean losing the tight connection to the bar that's necessary for an aggressive turnover. Waiting too long will mean that the full weight of the bar is already pushing down into the hand and the hook will not release. The thumb should be slipped out without opening the hand or relaxing the grip any more than necessary at the moment the hand is flipping over. That is, as the lifter transitions from pulling against the bar to pushing up against it, there will be an opportunity to relax the grip and allow the thumb to slide out without resistance or losing the connection to the bar.
This timing can be difficult to perfect and it may take a lot of practice. Muscle snatches
can be used as a way to practice the release in somewhat slower conditions, but ultimately the timing needs to be learned with the full speed lift.